Projects 302 GMC SIx or a Pontiac OHC Sprint Six?

A OHC fan here. Owned a couple and they both did just fine. There is a great Sprint forum that can help with questions and parts.

 

Here's one that is stroked to 302.....Pardon the O.T. car.



I'm leaning towards the OHC. After all, when I first looked at the car, that is the engine that first popped into my head. It just felt like a natural fit, in a 41 Pontiac that was originally a 6 cylinder car.

It'll probably depend on how tough it is to find a good OHC, with the Q-jet and dual exhaust manifold. They have to be one of the sharpest looking inline sixes, ever built.

 

I had a Clifford intake on mine. You may still be able to buy one new from them.

 

Just saw one for sale. Either in The Hamb classifieds, or on that auction site. Weren't the factory intakes made of cast iron?

 

I dont know but i am really liking that ohc

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Yes. Factory was iron. Clifford was aluminum. I had to make 1/2 inch spacers to move mine out as it would not come close to clearing the Clifford headers.

 

I've found a few OHC engines, including a couple of 4 bbl. engines. However, the one that sounds the best, (a running in the car, freshly rebuilt 4 bbl. engine), is about 4 - 5 hours away, in Michigan. The price is nice, though. $950 for the complete engine.

Another possibility is a 1954 331 Caddy. I already have the Caddy, but am not too sure how well a T-5, (NWC out of an 85 S-10), would hold up behind it. Plus the Caddy needs bored, new pistons, etc.

 

I thought you said you already had an OHC six? If you have to go buy one I might have to rethink my answer.

 

I already have a small port 270 GMC. It's a complete engine from pan to air cleaner. However, it has a stuck valve, and smoked really bad when I had it running about 15 years ago. I pulled it out of a 56 350 series GMC that I parted out to build my 59 GMC pickup. I also have an easy source for a 302 GMC short block that is still in the GM crate. One of my nephews has the 302 and a used big port head.

I've been looking for a OHC Pontiac. I don't have any spare parts for the OHC either.

I also have a 331 Caddy along with a stick bellhousing adapter. It's in my 34 Chevy, but I'm thinking of getting a 390 Caddy for the 34. Like the saying goes.......There is no substitute for cubic inches. By the way, the 34 is being built as a late 1950's - early 1960's drag car and will get run at The Meltdown Drags. That is, if I ever get it finished. LOL.



On top of all this, I have a good remanufactured 235 Chevy that I pulled out of my 59 BelAir. It has maybe 2000 miles on it. I've read that Canadian Pontiacs used 261 Chevy sixes. Did the Pontiac 261's have a Pontiac script valve cover?

 

http://www.jalopyjournal.com/forum/threads/gmc-302-270-engine-and-parts-collection.1031930/

 

Even though the Pontiac is a higher ticket cost wise, I'd do it. But I'm odd that way. It may to be plentiful but it wasn't the mechanical issue with the cam bearing's that killed that engine. It was just to tall of a set up to fit in with the future design of body styles to come. So it was dumped . There are very supportive forums out there to help with sourcing proper machine work and part's for the top end of it. After all, the bottom end is just like all other engines. Good Luck with which ever you choose.

 

I ran an Algon injected OHC Pontiac in my roadster at el mirage and Muroc. It was once owner by Eddie Meyer and was in a 5 liter race boat. It had a dry sump, Electromotive ignition and some rocker arms converted from a Mercedes engine. It also had a 292 Chev 6 crank and as remember it wasn't too big of a deal to put it in. 4-1/8" stroke makes a lot of torque. Vic Enyart had it at that time and I have no idea where it is now.

 

The big swap meet in Jefferson Wis. is next weekend. Perhaps an OHC will show up there.

 

Looks like it's going to get a 302 GMC. I never found a good Pontiac OHC Sprint Six engine that was close enough, complete enough, and in good enough condition .

Since the 302 is only about 5 miles away, that will make it easy. It's a NOS short block that is still in it's, (cardboard), crate. Plus my nephew owns it. It has a boss for a mechanical fuel pump, so I assume that it's a civilian block??? Not a military block???

The head is off of a mid 1950's Army 6x6. Unfortunately, the head sat outside for a LONG time. Several valves were stuck, and a couple of the plugs were snapped off. Have been soaking the head in Kroil for the last few weeks and got the valves freed up. The four unbroken plugs came out OK. However, the ones that were broken off are still stuck in the head.

Will be taking the head to the machine shop to get checked for cracks. Hopefully, they can do something about the broken off plugs.

 

too bad I didn't see this earlier as a guy in St john Ind ( chicago craigslist) had 2 OHC's for sale ( 1 runner from a firebird and a unit for parts .

only problems I remember with them was the wrist pins in the early ones would cause a knock .

 

GMC 302

 

The T-5 will not attach to the 302 with out a custom adaptor. If you're looking for power, vintage look and reliability, I put a 292 with some goodies in my '40 Chevy. T-5 bolted up, make lots of power with little add on's, and the look factor isn't bad either! Can find parts at the local auto parts store too!

 

Just bought this 1966 230 OHC to put in my 34 chev pick up truck . rebuilt 60 over 10 10 n the crank. Man what a smooth running motor.
Now who is hoarding the 4 barrel intake and split exhaust

 

I ran into one of those 4 bbl intakes with dual exhaust at a swapmeet but the seller did not know what it fit and I never seen one before so I passed on it.

 

Oh yeah , go ahead and break my heart LOL